Women could totally date a fat guy with a good attitude and "fix him" by encouraging him to work out and eat better, thus getting a man with both looks and personality.
Women could find an insecure loser nerd with potential, and "fix him" by building him up.
But instead they choose to chase after Chads and "fix them" by trying to change their personality.
Conclusion? Women just care about their base primal needs. Everything beyond that is just a rationalization.